top of page

Blood Sugar Monitoring

Updated: Nov 9, 2020

As a diabetic, you’ll need to take a lot of active steps to keep your health in check.

If you have been diagnosed with diabetes, it’s important to know that you’ll need to take a lot of active steps to keep your health in check. One of these steps includes testing your blood glucose level, as the main goal of treating diabetes is to keep blood sugar levels in a normal range. Successful diabetes treatments involve making positive lifestyle changes, taking medicine, and consistently monitoring your blood sugar.

Your healthcare provider will periodically order a blood test to determine your A1C (glycated hemoglobin) and blood sugar levels. This test is administered to determine your overall blood sugar from the last two to three months. It is also pertinent that you do your own blood sugar monitoring. Self-blood glucose monitoring allows you to know your blood glucose level at any time. Knowing your levels will help prevent that often dangerous consequences of very high or very low blood sugar. Monitoring will allow you to fine-tune your blood glucose levels and gain tighter control over your blood sugar, which decreases long-term risks of diabetic complications.


How frequently you need to test your blood glucose levels depends on two factors:

  1. The type of diabetes you have— Type 1 or Type 2

  2. Which treatments you use— insulin, oral medications, or making lifestyle changes

Type 1 Diabetes

Individuals diagnosed with type 1 diabetes will need to test their blood sugar levels at least four times a day. For those who use an insulin pump, give three or more insulin injections per day, or are pregnant, you may need to test up to seven times a day, if not more.

For patients who have to test four to seven times a day, you may consider purchasing several blood glucose monitors. That way you will be able to keep one at school, work, home, or to keep in your bag while you’re traveling. By giving yourself easier access to testing equipment, you are further improving your blood sugar control, limiting chances for emergency.

Type 2 Diabetes

It is just as important to monitor your blood sugar when you have type 2 diabetes. The amount of times you should administer self tests is dependent on several factors such as, type of treatment (diet, oral medication, or insulin), your A1C levels, and overall treatment goals.

Your doctor or nurse will be able to help you determine how often you’ll need to test your blood sugar both by yourself, and by a doctor.


Interpreting Blood Sugar Results

The results of your blood sugar testing will be able to tell you whether or not your diabetes treatment is effective. It’s important to remember while monitoring your own blood sugar, that levels can be affected by activity levels, the foods you’ve eating, and any medications. By considering these factors, you’ll be able to clearly interpret your results.

You should always review your results on a regular basis with your healthcare provider. Keep a record of the date, time, blood glucose result, and dose of medication used. It’s helpful to keep additional notes about what you ate, any exercise you did, and difficulties with illness or stress. These detailed records can be extremely helpful for your doctor, however they’re always a daily requirement.

Adjusting Treatment Accordingly

Once you’ve gotten the hang of doing at-home blood sugar monitoring, and interpreting those results thereafter, you will be able to confidently adjust your treatment if necessary. If you use insulin, you will be able to determine the appropriate dosage from meal to meal.

In the beginning, you’ll need to consult with a healthcare provider, but with time and experience most people are able to safely and effectively make adjustments on their own.


The absolute best way to determine the accuracy of your blood glucose monitor is to bring it along with you on a visit to your doctor’s office. Use your at-home monitor at the same time your blood is being drawn. There should be no more than a 15 percent difference in the results. Larger differences could indicate a problem with your monitor, blood glucose strips, or your monitoring technique.

Blood Glucose Monitors

Blood sugar monitors are reasonably accurate. However, there might be some variability from one unit to the next. Be sure to exercise caution, and utilize common sense when interpreting the results from these machines. If your readings are not cohesive with your symptoms, or lack thereof, take a second reading or use an alternate method for testing your blood sugar (such as a different meter). Not that blood glucose meters are the least accurate during episodes of low blood sugar.

Alternate Site Testing

Fingertip testing is the most accurate site to test your blood sugar. Results can be less accurate if you test at places such as your arm, hand or leg. When your blood sugar is rising rapidly (e.g. immediately after eating) or falling rapidly (in response to insulin or exercise), testing at a site other than the fingertip may give you significantly different results. In these situations, fingertip testing is preferred.



Continuous Glucose Monitors are most commonly used in patients with type 1 diabetes. Medical experts believe that CGM systems are most useful for people who have a difficult time recognizing when they have low blood sugar. Continuous Glucose Monitors use a glucose sensor that is contained in a small needle inserted under the skin, and attached with a sticky patch. The sensor will then wirelessly transmit your blood sugar level results to a recording device roughly the size of a cell phone that you can carry with you in a purse or bag. This monitor will update and display your results every few minutes.

It’s extremely important that you remove and replace the sensor in a different place on your body approximately once a week. You must also continue to perform blood sugar testing from your finger several times a day to ensure that your CGM is calculating your levels correctly.


Having a CGM can be very advantageous to monitoring your overall health. The stronger grasp you have on knowing your blood sugar levels, the more proactive you can be about maintaining normal or near normal levels.

The Continuous Glucose Monitor will display your blood sugar level every few minutes, which allows you to determine if your level is increasing, decreasing, or if it’s stable. Most receivers can be set to notify you if your blood sugar level is above or below a pre-set level. This is especially helpful for individuals who are unable to tell when they have low blood sugar, otherwise known as hypoglycemia unawareness.

You can download your blood sugar results from your CGM to your computer, which allows you to see your blood sugar trends over time. You can share this information with your physician, and determine whether or not you need to adjust your insulin dosage.


The primary issue with CGM systems is that the sensors currently available are not as accurate as most blood glucose monitors, specifically when your blood glucose levels are rapidly rising or when they are extremely low (less than 70 mg/dL or 3.0 mmol/L). One study determined that over 70 percent of actual blood sugar levels and the levels shown on a CGM differed by 10 percent or more. Nearly 7 percent of the readings had differed by over 50 percent.

Most experts do not recommend using a Continuous Glucose Monitor alone to determine your blood sugar levels. It’s strongly suggested that you still do several fingerstick tests a day to calibrate your CGM device and verify that the sensor readings are accurate.

In addition to possible inaccuracy, the general cost of a CGM system is much greater than the overall costs of traditional glucose monitors. It’s important to note that not all Continuous Glucose Monitors and additional supplies are covered by commercial health insurance companies.

12 views0 comments
bottom of page